A prior art vibrating fiber optic display unit is shown and described in U.S. Pat. No. 4,311,999, issued Jan. 19, 1982. A vibrating cantilever beam portion is shown and described in a publication, entitled "Proceedings of IEEE, Volume 70, Number 5, May 1982".
The prior art display unit includes, a cantilevered fiber optic ribbon, an electromechanical drive means for vibrating the ribbon, light emitting diode means for transmitting light through the ribbon to form a display, an optocoupler for detecting the position of the ribbon and for controlling the diode means in response to input signals to form the ribbon display.
One problem with the prior art display unit is that the drive means needs to be manually tuned to match the ribbon resonant frequency, which varies with temperature and which varies with ribbon mass and length.